The present novel concept broadly relates to the art of fluid suspension members and, more particularly, to an air spring assembly suitable for operation at increased air pressures as well as a corresponding method of manufacturing the same.
Air spring assemblies of various kinds and constructions are well known and commonly used. Furthermore, such air spring assemblies are typically available in a wide variety of sizes and load capacities. Even so, air spring applications continue to be developed that demand greater air spring performance, often in increasingly smaller packages. Such improvements in performance can include increased load capacity and greater stroke length, for example.
One way that the load capacity of a given air spring assembly can be increased is by increasing the air pressure within the spring chamber thereof. As such, it is also possible to use an air spring assembly having a reduced size (e.g., a reduced diameter), while maintaining a given load capacity at the desired nominal height, by operating such an air spring at a corresponding higher air pressure level. It will be appreciated that air spring assemblies are typically operable over a range of nominal air pressures. However, operation of an air spring at a pressure level slightly outside this range will normally be well within the capabilities of known air spring designs.
It will be appreciated, though, that operating an air spring assembly of traditional construction at a significantly increased air pressure level, such as at about double the nominal pressure level, for example, can lead to the development of various problems and difficulties. For example, in some cases the flexible wall extending between the end members of the air spring assembly may not be suitable for operation at greater pressure levels. Recently, though, improved flexible wall materials have been developed that are better suited for operation at these increased pressure levels.
Another difficulty that can develop with the operation of known air spring assemblies at such elevated air pressure levels is related to the securement of the flexible wall to the end members of the air spring assembly. That is, in such arrangements, leak paths can develop between the flexible wall and an end member of the air spring in areas that normally form a fluid-tight seal at standard operating pressures. This is undesirable, and can lead to increased consumption of compressed air as well as decreased performance of the air spring assembly and/or any associated system. Additionally, it is in some cases even possible for some amount of separation of the flexible wall from the end member to occur. This can undesirably result in movement of the sleeve and/or any retaining member relative to the end member.
Attempts have been made to overcome these problems by increasing the retaining force generated by the retaining member, such as by crimping or otherwise more tightly deforming the retaining member toward the sleeve and end member, for example. However, such attempts have generally met with marginal success and the development of leaks and even some movement of the flexible sleeve and retaining member remain problematic.
Other attempts have been made to improve the fluid-tight connection between the flexible sleeve and the corresponding end member by utilizing a retaining member having a greater height. These efforts have met with some success in certain applications. However, such arrangements tend to undesirably increase the length of the end member and thereby reduce the travel or operating stroke of the air spring assembly. As indicated above, it is generally desirable to increase the operating stroke of the air spring assembly and/or reduce the overall size thereof. Thus, in many applications a retaining member arrangement that increases the size of the end member and/or reduces the stroke of the air spring assembly is not desirable.